A packaging technique for achieving device lightness, slimness and compactness has been actively researched. In this regard, it is very important to ensure reliability of a package against thermal stress in a manufacturing process or a use environment.
Such thermal stress may occur intensively at contact points between dissimilar materials. Particularly, stress occurring at a point at which a redistribution layer and a passivation film of a semiconductor chip contact each other may cause serious reliability problems, such as causing cracks. 